River level and flow gauges along the Thames give you an idea of how fast the river is flowing and how likely it is to flood.
Sunbury
What does the Sunbury lock water level mean at the club house?
5.05m : water lapping over step to club house, canoe drying area under water (all time peak reached on 11.02.14)
4.95m : car park under water, canoe drying area a bit wet
4.50m : car park half under water, canoe drying area high and dry
4.00m : car park dry but river still in flood
3.19m : flooding possible in Sunbury